Frequency discrimination in the presence of another tone

Abstract

The effects of an interference tone on frequency discrimination of a brief tonal signal were investigated. The interference tone was 500 msec in duration and the same intensity as the signal. Changes in frequency discrimination were measured as a function of signal duration, the frequency separation between the interference tone and signal, and the temporal delay between the two. Both ipsilateral- and contralateral-interference conditions were investigated. The addition of an interference tone significantly degraded preformance in only one condition: 10-msec signal, trailing interference tone delivered to signal ear. For all other stimulus configurations, frequency discrimination was unaffected by the presence of the interference tone. These data are generally consistent with analogous sensory masking effects characterizing backward and forward masking and do not support cognitive-perceptual models of pitch and recognition.